The objectives of this research are to identify electrical, neural and hormonal controls of gastrointestinal motility in health and disease. Using in vivo techniques in man and dogs, electric activity will be studied using silver electrodes, motility using balloons, open-tipped catheters, strain gauges, cinefluorography, and emptying using radioactive metals, plastic spheres and solutions. Control patterns will be stressed by electric pacing, by administering pure hormones and chemicals, and by operations. BIBLIOGRAPHIC REFERENCES: Kelly, K.A.: The Effect of Pentagastrin on Canine Gastric Myoelectric and Motor Activity. Gastrointestinal Hormones. J.C. Thompson, Editor. pp. 381-389, University of Texas Press, Austin, 1975. Akwari, O.E., Kelly, K.A., Steinbach, J.H. and Code, C.F.: Electric Pacing of Intact and Transected Canine Small Intestine and its Computer Model. Am. J. Physiology 229:1188-1197, 1975.